cos^2x-sin^2x=COS2X我知道,我想要详细步骤
f(x)=2cos2x+sin^2x,化简.详细步骤!
求证 cos^8(x)-sin^8(x)=cos2x【1-1/2sin^2(2x)】
化简:2cos2x+2sin^2 x+cos(-x)分之sin2x+sin(π-x)=___________
sin(x+y)-sinx=2cos(x+1/2y)sin(1/2y)的详细证明步骤.
[sin^2(x)-cos^2(x)] 为什么等于-cos2x
已知cos2X=根号2/3,则sin^4X+cos^4的值为?求详细过程!
f(x)=(1+cos2x)/[4sin(pai/2+x)]-asin(x/2)cos(pai-x/
谁能够帮我求下函数定义域,y=arc sin (2x-1)/7,我想要信息步骤,
已知函数f(x)=(6cos^4x+5sin^2x-4)/cos2x
函数f(x)=cos2x+cos(x+π/3)+sin(x+π/6)+3sin^2x的最小值
求证:sin(π/4+x)/sin(π/4-x)+cos(π/4+x)/(π/4-x)=2/cos2x
已知sin(x/2)+cos(x/2)=1/2,则cos2x=?